Thank you. This was helpful
I have learned that you can in fact message your self in the Shortcuts apps.
You can also do a simple notification motion detected directly from the motion sensor in the HomeKit app.
Also, Controller for Homekit app offers some very sophisticated notifications and actions you can take.
Still, I wish someone out there would write a good book or that there was a site where you could go that offered useful HomeKit solutions to share with interested users. Then, everyone would not have to "reinvent the wheel" for themselves to get their homes to do what they want. They could simply follow an example (such as yours) rather than having to learn the hard way.
As I said before not everyone is adept at HomeKit programming.